Multiband quad and loop antenna

ABSTRACT

An antenna which incorporates a single four-sided radiating element or loop in conjunction with series or parallel connected loading units to cover a multiple of operating frequencies.

United States Patent [191 [111 3,737,907 Monola [4 June 5, 1973 [54]MULTIBAND QUAD AND LOOP 3,623,110 ll/l97l Dol et al ..343/744 1 ANTENNAPrimary ExaminerEli Lieberman [75] Inventor. WIIbert E. Monola, Erie,Pa. Attorney charles L- Lovercheck [73] Assignee: Mini-Products, Inc.,Erie, Pa.

22 Filed: June 30, 1971 ABSTRACT [211 Appl. No.: 158,424 An antennawhich incorporates a single four-sided radiating element or loop inconjunction with series or llel connected loadin units to cover a multiis of 52 .Cl. 43 744 343- 730, 343 752 Pm A g P {51} Cl. ...H01q 1 1/12peratmg [58] Field of Search ..343/725, 726, 741, 343/744, 730, 752

[56] References Cited I 7 Claims, 7 Drawing Figures UNITED STATESPATENTS Saranca ..343/744 PATENTEU JUN SHEET 1 OF 2 a: ht

Uwwn WILBERT E.MONOL.A AA. f 11%;; W

1 MULTIBAND QUAD AND LOOP ANTENNA REFERENCE TO PRIOR ART The loadingunits used on the antenna disclosed herein are described fully in myprevious US. Pat. No. 3,089,140.

GENERAL DESCRIPTION OF INVENTION The loading units are mounted 180 apartat the high voltage points of the radiating element, thereby effecting asubstantial reduction in physical size and, at the same time, retainingthe maximum current-carrying portion of the radiator for most efficientradiation.

The loading units may be either series or parallel connected and areattached 180 apart to the high voltage points of the four-sided quad orloop radiator with the transmission line or feed point situated midwaybetween. The antenna operates as an electricalfull wave loop on allfrequencies for which it is designed. These single multiband elementsmay be combined on a common boom or structure to form higher gain,directional multi-element arrays such as two and three element quads.

OBJECTS OF THE INVENTION It is, accordingly, an object of the presentinvention to provide a multiband quad or loop antenna whose physicalsize is determined by the highest frequency ofdesired operation ratherthan the lowest frequency as with conventional multiband quad antenna.

Another object of the invention is to provide an improved miniatureantenna suitable for operation over a plurality of frequencies.

Yet another object of the invention is to provide an improved multibandantenna suitable for restricted and limited space installation.

Still a further object of the invention is to provide a multibandantenna which is simple in construction, economical to manufacture, andefiicient to operate.

With the above and other objects in view, the present invention consistsof the combination and arrangement of parts hereinafter more fullydescribed, illustrated in the accompanying drawings and moreparticularly pointed out in the appended claims.

GENERAL DESCRIPTION OF THE DRAWINGS FIG. 1 shows a single elementfour-band quad antenna.

FIG. 1A is an enlarged view of one of the loading units connected to theradiator as shown in FIG. 1.

FIG. 2 shows a circular radiator with multiband loading units mountedl80 apart at the high voltage points of the radiator.

FIG. 3 shows a modified elliptical radiator with multiband loading unitsmounted l80 apart at the ends of the radiator.

FIG. 4 shows a schematic drawing of a parallel connected four-band quadantenna.

FIG. 5 shows a schematic drawing of a series connected four-band quadantenna.

FIG. 6 shows a two-element four-band quad antenna with reflector anddriven element.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the embodimentshown in FIG. 1,

FIG. 1 shows a single element four-band quad antenna comprising a wireradiator 11 fastened to the four ends and loading capacitor,

The metallic sleeve 25 shown in FIG. 1A should have a diametersufficiently large to support coil form 19. Coils 36, 37 and 38 areconnected to the corner of the radiator 11 through the metallic sleeve25. The cross member 41 is made of insulating material. The loadingcapacitors, consisting of rings 31 and spokes 43 are supported on thecoil form, as shown. The spokes 43 are made of conducting material andhave reduced size threaded ends which engage the mounting rings 31.

The embodiment of the invention shown in FIGS. 2 and 3 are similar tothe embodiment shown in FIG. 1, however, they have circular and ovalshaped radiators. The parts corresponding to the parts shown in theembodiment of FIG. 1 have added to them in the embodiment of FIG. 2andhave 200 added to them in the embodiment shown in FIG. 3.

The embodiments shown in FIGS. 4, 5, and 6 show schematic views of afour-band quad antenna in FIGS. 4 and 5 and a two-element four-band quadantenna in FIG. 6 with reflector and driven element. The driven elementin FIG. 6 is indicated at 511 and the feed line connecting board isindicated at 524. The reflector element is indicated at 526. I

The foregoing specification sets forth the invention in its preferredpractical forms but it is understood that the structure shown is capableof modification within a range of equivalents without departing from theinvention which is to be understood is broadly novel as is commensuratewith the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An antenna comprising a radiator consisting of a single continuousloop of wire forming a geometrical configuration and having two spacedends adjacent each other, and having a total distance around the loop ofapproximately one wave length at a predetermined frequency,-

two terminals disposed adjacent each other, one said terminal beingconnected to one said end and the other said terminal being connected tothe other said end of said loop, said radiator having a pair of loadingunits each comprising a series connected inductor and loading capacitormounted apart at the high voltage points of said radiator and beingconnected thereto to extend outwardly along an axis of symmetry,

said inductors having a sufficiently high impedance to act as a radiofrequency choke at said predetermined frequency,

said inductors and said loading capacitors acting as an additionalelectrical length to said radiator at a lower frequency than saidpredetermined frequency, thus providing operation on two differentfrequencies. 2. The antenna recited in claim 1 wherein a second inductorwith a loading capacitor in series therewith is connected in series withsaid first mentioned inductor said second inductor being of a value toact as a radio frequency choke at said lower frequency and to act as anadditional electrical length to said radiator and said first inductorand loading capacitor at a still lower frequency then said lowerfrequency,

thus allowing operations on three frequencies. 3. The antenna recited inclaim 2 wherein a third in- V ductor and loading capacitor are connectedin series quency lower than said radiators predetermined frequency.

5. The antenna recited in claim 1 wherein a second inductor with aloading capacitor in series therewith is connected inparallel at theinductor end with said first mentioned inductor and to said radiator,

said second inductor and capacitor being of a value to act as a radiofrequency choke at said lower frequency and to act as an additionalelectrical length to said radiator at a still lower frequency than saidlower frequency and thus allowing operation on three frequencies.

6. The antenna recited in claim 5 .wherein a third inductor with aloading capacitor in series therewith is connected in parallel at theinductor end with said first and second mentioned inductors and to saidradiator,

thus providing operation on four frequencies.

7. The antenna recited in claim' 1 wherein a multiple of inductors withloading capacitors in series therewith are connected in parallel at theinductoriendwith said first mentioned inductor and to said radiator toprovide a multiple of frequencies lower than said radiator frequency.

1. An antenna comprising a radiator consisting of a single continuousloop of wire forming a geometrical configuration and having two spacedends adjacent each other, and having a total distance around the loop ofapproximately one wave length at a predetermined frequency, twoterminals disposed adjacent each other, one said terminal beingconnected to one said end and the other said terminal being connected tothe other said end of said loop, said radiator having a pair of loadingunits each comprising a series connected inductor and loading capacitormounted 180* apart at the high voltage points of said radiator and beingconnected thereto to extend outwardly along an axis of symmetry, saidinductors having a sufficiently high impedance to act as a radiofrequency choke at said predetermined frequency, said inductors and saidloading capacitors acting as an additional electrical length to saidradiator at a lower frequency than said predetermined frequency, thusproviding operation on two different frequencies.
 2. The antenna recitedin claim 1 wherein a second inductor with a loading capacitor in seriestherewith is connected in series with said first mentioned inductor andloading capacitor, said second inductor being of a value to act as aradio frequency choke at said lower frequency and to act as anadditional electrical length to said radiator and said first inductorand loading capacitor at a still lower frequency then said lowerfrequency, thus allowing operations on three frequencies.
 3. The antennarecited in claim 2 wherein a third inductor and loading capacitor areconnected in series with each other and with said second inductor andsaid second loading capacitor, thus allowing operation on fourfrequencies.
 4. The antenna recited in claim 2 wherein a third inductorwith a loading capacitor in series therewith is connected in parallel atthe inductor end with said first mentioned inductor and to said radiatorand acting as an additional electrical length to said radiator at afrequency lower than said radiator''s predetermined frequency.
 5. Theantenna recited in claim 1 wherein a second inductor with a loadingcapacitor in series therewith is connected in parallel at the inductorend with said first mentioned inductor and to said radiator, said secondinductor and capacitor being of a value to act as a radio frequencychoke at said lower frequency and to act as an additional electricallenGth to said radiator at a still lower frequency than said lowerfrequency and thus allowing operation on three frequencies.
 6. Theantenna recited in claim 5 wherein a third inductor with a loadingcapacitor in series therewith is connected in parallel at the inductorend with said first and second mentioned inductors and to said radiator,thus providing operation on four frequencies.
 7. The antenna recited inclaim 1 wherein a multiple of inductors with loading capacitors inseries therewith are connected in parallel at the inductor end with saidfirst mentioned inductor and to said radiator to provide a multiple offrequencies lower than said radiator frequency.